Here is the full list of all 24 Oracle achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Visit the railroad and the train wreck.
Find the old outpost by the river.
Visit the ruins.
Cross the wooden bridge.
Explore the tombstones.
Walk under the waterfall.
Red tree inside the Pit?
Find the hidden passage.
Magic under the Roar.
Visit the Tower.
Remember her neck tattoo.
Explore the boats by the shore.
Find the grave of the Fallen.
Explore the maze.
Find the Gorge.
Explore the mine that goes on top of the mountain.
Explore the Radio Station.
Explore the wooden windmills.
Explore the corn field.
Explore the wrecked coal mine.
Swords and Skulls.
Explore the Graveyard.
Explore the Church.
Wake up on the Island.